A friend recently showed me a newsletter he receives from a company that sells vitamins and dietary supplements; an article in it warned that disinfectant byproducts in public drinking water are a serious health risk. The author referred to a paper published by researchers at the University of Illinois that shows some of these compounds kill cells and cause DNA damage (Pals, J.A., et al., 2011. Biological mechanism for the toxicity of haloacetic acid drinking water disinfection byproducts. Environmental Science & Technology 45:5791–5797). The author then states that unless you have a deep private well that you can test and trust, you should consider buying a distillation system. While disinfection byproducts are no joke and are regulated by the Environmental Protection Agency, I think the author overstates the problem and its solution.
Disinfection byproducts are formed when a disinfectant added to water, typically chlorine or a chlorine compound, reacts with naturally occurring dissolved organic matter. Compounds such as trihalomethanes and haloacetic acids can be formed, and these have been shown to increase the risk of urinary bladder cancer and adverse pregnancy outcomes. Your public water supplier produces an annual water quality report that reports, among other things, the concentrations of regulated disinfection byproducts. Here’s a link to the most recent report for Champaign’s water (Illinois American). By law, public water supplies cannot exceed the drinking water limits for these compounds (or any other regulated chemicals).
If you are still concerned about these compounds in your drinking water, there are products you can buy for your home (google “disinfection byproducts removal”). It’s not something I am personally concerned about or would recommend. Remember that every treatment process that is used, either by you or the water utility, costs money, and I’m not yet convinced that these additional treatments are worth the cost. Meanwile, researchers continue to develop and test new disinfection techniques to minimize these issues.
The statement the newsletter author makes about deep private wells is somewhat misleading. While microbial contamination is uncommon in deep wells, there are other potential contaminants that might need to be treated for. Some deep wells in Illinois, for example, have elevated levels of natural contaminants such as radium, arsenic, and boron. And there are basically no water quality regulations for private wells, so you’re on your own to make sure your water quality is adequate.
